Baroness Thatcher has been given a ceremonial funeral at St Paul's Cathedral as Britain remembers a famous but divisive prime minister.
The Queen, her presence effectively raising it to a state event, joined dignitaries from around the world and all Lady Thatcher's successors.
It was the first time the monarch had attended the funeral service of a former prime minister since Sir Winston Churchill's state ceremony in 1965.
The UK's first and so far only female prime minister was given full military honours, her coffin brought to St Paul's on a gun carriage drawn by six black horses.
Lady Thatcher's family on the steps of St Paul's Cathedral
Security across the capital was tight but there appeared to be far smaller crowds than expected, with some areas where barriers were erected almost empty.
Scotland Yard said no arrests were made in London during the morning, although many onlookers were furious that taxpayers were paying most of the funeral bill.
Inside the famous church, more than 2,300 guests paid tribute, led by the former politician's children Mark and Carol and her two grandchildren Michael and Amanda.
Sitting a few rows behind them among today's parliamentarians was Chancellor George Osborne, who had tears running down his face.
An aerial view of St Paul's as the coffin arrived
Aides to the Cabinet minister declined to elaborate on his emotional response, saying it "speaks for itself".
More than 30 members of the Iron Lady's cabinets, including Lord Heseltine and Lord Howe who played a key role in her downfall, were at the service.
Alongside them were dignitaries from around 170 countries, including two heads of state and 11 serving prime ministers.
No-one from the White House was there, but former US vice-president Dick Cheney and ex-secretary of state Henry Kissinger attended in a private capacity.
More than 50 guests were associated with the Falklands, including one of the conflict's most well-known veterans Simon Weston.
Chancellor George Osborne shedding a tear during the service
Figures from the entertainment world included Sir Terry Wogan, Jeremy Clarkson, Katherine Jenkins, Joan Collins and Lord Lloyd-Webber.
The main service was conducted with more pomp and ceremony than any funeral seen in London since the death of the Queen Mother in 2002.
Lady Thatcher had planned it to the last detail and at her express wish, her granddaughter Amanda read the first lesson.
David Cameron read from the Gospel and the Bishop of London gave an address which deliberately steered clear of talking about her political legacy.
He said: "The storm of conflicting opinions centres on the Mrs Thatcher who became a symbolic figure - even an "ism".
"Today the remains of the real Margaret Hilda Thatcher are here at her funeral service. Lying here, she is one of us, subject to the common destiny of all human beings.
"There is an important place for debating policies and legacy; for assessing the impact of political decisions on the everyday lives of individuals and communities.
David Cameron doing a reading in front of the coffin
"Parliament held a frank debate last week - but here and today is neither the time nor the place."
Music by British composers was played at the beginning and end of the service, and the hymns reflected aspects of Lady Thatcher's life.
They included He Who Would Valiant Be, Love Divine All Loves Excelling to mark the influence of her Methodist upbringing and I Vow To Thee My Country because of her love for the nation.
At the end, the Archbishop of Canterbury Justin Welby gave the blessing before the coffin was removed by bearers from units linked to the Falklands War.
The Queen greeting Mark and Carol Thatcher outside the church
The waiting crowd gave three cheers as it emerged, after which the Queen and Duke of Edinburgh joined Lady Thatcher's family on the Cathedral steps.
The ceremony followed a sombre procession through central London, which was on lockdown with 4,000 police officers on duty in case of any unrest.
Many among those lining the streets appeared to be Thatcher supporters, although others booed or performed a silent protest as the coffin passed.
The honours had started at dawn with the lowering of flags over government buildings all around the country, where they will remain until dusk.
Big Ben then fell silent at 9.45am and did not chime again until 1pm, in a mark of respect from the institution that made Lady Thatcher's name.
Her coffin, which had rested in the Chapel of St Mary Undercroft in Westminster overnight, was removed from Parliament at 10am.
The Blairs and the Camerons were in the congregation
People applauded as the hearse made its way up Whitehall past Downing Street - the politician's home for more than a decade.
A hand-written card from her two children placed in a single large white flower arrangement resting on the coffin read: "Beloved mother, always in our hearts".
Transferred to a gun carriage outside St Clement Danes Church, it was then escorted by hundreds of troops to St Paul's for the service.
The 1.5 ton carriage travelled at 70 steps per minute - its wheels changed from steel to rubber so that it ran more quietly along the road.
During the procession, a gun salute was fired at one-minute intervals from the Tower of London.
Among the three 105mm light guns operated by the Honourable Artillery Company were two used in the Falklands and last fired in anger at Goose Green and the final assault on Port Stanley.
(L-R) Lords Tebbit, Howe and Heseltine outside St Paul's
At St Paul's, the cortege was met by a guard of honour from the 1st Battalion Welsh Guards on the steps which were lined by members of all three services and 16 Chelsea pensioners.
As crowds packing the pavements applauded warmly, a single half-muffled bell tolled before the 55-minute service began.
After the ceremony, Lady Thatcher's family and guests went to a reception in the City of London ahead of a private cremation. Her ashes will be interred at the Royal Hospital Chelsea.
Dozens of onlookers lined the street and applauded as the funeral cortege arrived at Mortlake Crematorium in south-west London.
Ahead of the funeral, David Cameron insisted that his predecessor had settled divisions by winning the big arguments - declaring: "In a way, we are all Thatcherites now."
He added: "She was the first woman prime minister, she served for longer in the job that anyone for 150 years, she achieved some extraordinary things in her life."
Outside St Paul's supporter John Loughrey, from Wandsworth, said: "She saved Britain. She gave my father the opportunity to buy his council house.
The gun carriage entering Fleet Street
"We had all sorts of problems and Mrs Thatcher put it all back together again. We needed the Iron Lady."
Margaret Kittle, 79, had travelled all the way from Canada to pay her respects and was in place on Tuesday to ensure a good view.
She said: "My family came to Churchill's and I wanted to come to Maggie's because they are the two greats of history. We will never see the likes of Mrs Thatcher again."
But student David Winslow, 22, was among the critics in the crowd.
"The message is that spending £10m on such a divisive figure in times of austerity, especially when austerity is being imposed on the poor, is wrong, especially when harm is being caused to the disabled and the NHS," he said.
There was also tension between supporters and protesters near the Royal Courts of Justice, where pensioner Phil Williams held a banner saying "Rest in Shame".
A 45-year-old protester called Helen, who was wearing a mask of Lady Thatcher's face, said: "I think it's really scandalous that we've spent all this money and time on her funeral. It just adds insult to injury.
"I think she ruined Britain's manufacturing industry, which is something the current Government are always harping on about.
"I think she started the culture of vilifying the poor and the disabled and I just think the current Government are following Thatcher's policies."
Protesters angry that taxpayers' paid for most of the funeral
Cabinet Office minister Francis Maude said the cost of the funeral to the taxpayer would be "much, much less" than the £10m reported.
Many mining towns ignored the funeral but in Goldthorpe, an effigy of the former prime minister in a noose was paraded and residents plan to burn a coffin later.
One home in the town displayed a huge sign saying: "The Lady's not for turning but tonight she'll be for burning."
Meanwhile in Glasgow, a rally was being held to remember the "industries and communities who suffered" during her premiership.
Prominent left-winger Tommy Sheridan, who helped lead the protests against the poll tax in Scotland, will speak at the event.
However, in Lady Thatcher's hometown of Grantham, dozens gathered to watch the funeral and to pay their respects.
Christine Taylor, 66, said: "I think people forget the way Britain was before she came to power. They forget the winter of discontent."
The hearse passing by the gates of Downing Street
"I felt Mrs Thatcher was somebody who was going to stand up for people. I know she has been divisive but I think she was a great leader."
In Belfast, Unionists marked the funeral in the traditional fashion by flying the Union Flag at half-mast on the City Hall despite recent tensions over a vote to reduce the number of days it is flown.
But Sky's Ireland correspondent David Blevins said Republicans were preparing for evening protests.
On Falls Road in west Belfast, they will honour 14 IRA hunger strikers who died when Lady Thatcher refused to grant them political prisoner status in 1981.
By mid-afternoon, a small group of Republicans - around 50-75 people - had already started protesting at Free Derry Corner in Londonderry.
Ken Clarke, who held a series of senior roles in Lady Thatcher's Cabinets, dismissed people celebrating her death as "adolescents making silly points".
Of the funeral service, he said: "Being as objective as I can be, she was the first woman prime minister. She was the longest-serving prime minister in modern times.
"And she changed the country on a scale which no other prime minister came near. She was a huge national personality so I think it was entirely suitable."